The circuit structure of an A/D (Analog/Digital) converter mainly has stepwise comparison structure, integral structure, flash structure, graded structure, pipeline structure and Δ-Σ oversampling structure and so on. The main circuit structure involved in high-speed and high-precision A/D converter is pipeline structure. The pipeline ADC (Analog-to-Digital Converter) is formed by the cascading of pipeline stages with the same structure under dual-phase non-overlapping clocks, except the last stage, each pipeline consists of an MDAC (Multiplying Digital to Analog Converter) formed by an operation amplifier (OPAMP) and a switch capacitor circuit and a comparator-based sub-ADC, and the pipeline stage has various factors such as non-ideal properties and mismatch errors and so on, which causes non-continuous hop points in the transmission curve and greatly limits the performance improvement of the high-speed high-precision pipeline ADC with the gradual shrinking of the process feature size becoming a main factor to limit the conversion precision of the pipeline ADC. It is very important to compensate and correct the errors with an effective correction technology to solve the effect of these errors to the performance of the pipeline ADC.
At present, the error compensation correction method of the pipeline analog-to-digital converter usually needs to interrupt the normal operation of the ADC to input a known test signal to acquire correction information, even so, there may be certain deviation between the error information extracted during test and the error information during practical operation, and at the same time, the change of the non-ideal properties and mismatch errors of the correction device over time and the surrounding environment (such as temperature change, component degradation, voltage change and so on) cannot be tracked; and at the same time, the normal operation interruption of the ADC during test and being different from the normal operation state of the ADC if the error measurement result has deviation cannot be avoided.